Practice exercise (made-up values, not clinical guidance). A 74 kg adult (BMI below 30) needs 30 kcal/kg/day. The tube feed provides 1 kcal/mL and runs by pump for 16 hours a day. At what rate R do you set the pump, in mL/h? Round to the nearest whole number.
74 kg30 kcal/kg/day1 kcal/mL16 h
R = mL/h
2.Enteral & parenteral nutrition calculationsHard
Practice exercise (made-up values, not clinical guidance). Over 24 hours a patient receives 1500 mL of parenteral nutrition with final concentrations of 17.5% dextrose and 5% amino acids, plus 500 mL of 10% lipid emulsion (1.1 kcal/mL). Find the non-protein energy NPC in kcal per day. Round to the nearest whole number.
1500 mLdextrose 17.5%amino acids 5%lipid 500 mL · 1.1 kcal/mL
NPC = kcal/day
3.IV fluids & fluid balanceMedium
Practice exercise (made-up values, not clinical guidance). The record shows a patient's intake and output for one 12-hour shift. The IV infusion ran at the rate shown for the whole shift. Find the total intake I in mL.
juice: 120 mLwater: 200 mLjelly: 120 mLIV infusion: 100 mL/h × 12 hIV antibiotic: 1 × 100 mL
I = mL
4.IV fluids & fluid balanceHard
Practice exercise (made-up values, not clinical guidance). A 1000 mL bag was started at 10:45 and runs by pump at 60 mL/h. How many mL V are left in the bag at 15:15?
1000 mL60 mL/h10:45 → 15:15
V = mL
3Solutions
1.Enteral & parenteral nutrition calculations
Answer: R = 139 mL/h
Needs and free water: energy needs are often estimated as kcal/kg/day × weight and protein needs as g/kg/day × weight. A formula is only partly water, so its free water = volume × water fraction; water flushes make up the rest of the daily fluid goal. Ideal body weight (Devine): IBW = 50 kg + 2.3 kg for every inch over 5 feet (60 in) for men, and 45.5 kg + 2.3 kg per inch over 60 in for women; 1 in = 2.54 cm. The formula is meant for adults at least 152.4 cm (5 ft) tall. The numbers are for practice only; at the bedside always follow local protocols and have high-risk doses double-checked.
Energy needed
E = 30·74 = 2220 kcal/day
Daily volume
V = 2220/1 = 2220 mL/day
Pump rate
R = 2220/16 = 138.8 ≈ 139 mL/h
Answer
R = 139 mL/h
2.Enteral & parenteral nutrition calculations
Answer: NPC = 1443 kcal/day
Parenteral nutrition: dextrose provides 3.4 kcal/g, amino acids 4 kcal/g and lipid emulsion the kcal/mL stated (2 kcal/mL for 20%, 1.1 kcal/mL for 10%). Grams = % × mL/100. Non-protein kcal (NPC) = dextrose + lipid kcal; nitrogen = protein/6.25. The glucose infusion rate (GIR) in mg/kg/min = dextrose mg/(kg × minutes). The numbers are for practice only; at the bedside always follow local protocols and have high-risk doses double-checked.
Grams of dextrose and amino acids
dextrose: 17.5·1500/100 = 262.5 g
amino acids: 5·1500/100 = 75 g
Kilocalories per component
dextrose: 262.5·3.4 = 892.5 kcal
amino acids: 75·4 = 300 kcal
lipid: 500·1.1 = 550 kcal
Non-protein energy
NPC = 892.5 + 550 = 1443 kcal/day
Answer
NPC = 1443 kcal/day
3.IV fluids & fluid balance
Answer: I = 1740 mL
Intake and output: intake counts everything that goes in (oral fluids, IV infusions, IV medications and flushes, tube feeds); ice chips count as half their volume. Output counts urine, drains, vomit and other losses. Balance = total intake − total output; a negative balance is a net loss. The numbers are for practice only; at the bedside always follow local protocols and have high-risk doses double-checked.
Add the intake
oral: 120 + 200 + 120 = 440 mL
IV infusion: 100·12 = 1200 mL
IV antibiotic: 1·100 = 100 mL
I = 1740 mL
Answer
I = 1740 mL
4.IV fluids & fluid balance
Answer: V = 730 mL
Infusion time: time (h) = volume to infuse (mL)/rate (mL/h); use the volume still left in the bag, not the bag size. Volume infused = rate × time. Convert decimal hours to hours and minutes with the fraction × 60 (0.5 h = 30 min, not 50 min). The numbers are for practice only; at the bedside always follow local protocols and have high-risk doses double-checked.